1. Field of the Invention
The present invention relates to a thermal type air flow measuring instrument for measuring an air flow taken into an internal combustion engine of an automobile, the instrument including a plastic part that is formed by integral molding with a metal part inserted therein.
2. Description of the Related Art
Japanese Publication of unexamined patent application No. 11-14423 discloses one example of the related art regarding a thermal type air flow measuring instrument using a molded part. In the disclosed instrument, a housing formed as a molded part comprises a frame shaped portion incorporating an electronic circuit therein and protecting it, a connector portion for electrical connection between an external device and the electronic circuit, and a fixing portion for fixing the thermal type air flow measuring instrument in place. Thus, the known thermal type air flow measuring instrument has a structure in which, by employing the housing, the electronic circuit is disposed in a flow duct and a metal base having mechanical strength is also disposed in the flow duct.